Hello,
I use DrDAQ for pH measurements and the readings are not correct with the picolog recorder, where the reading is stuck in a value around 7 in all cases. Moreover, readings shows 7.56 in 0.1mol/L HCl solution, and 6.74 is shown in 0.1mol/L NaOH solution.

This situation is quite the same also in Parallel Port and USB Parallel Port
Adapter.

I use picolog recorder rerease R5.20.1 and Windows Vista Home Premium SP1.

Thank you.
Each solutions of 0.1mol/L HCl(Factor 0.999) and 0.1mol/L NaOH(Factor 1.002) are both volumetric analysis solution. I am using these solutions for the neutralizing titration.When I measured them by other pH meter, they indicate 1.01 and 13.01 respectively.
DrDAQ displays a wrong pH though the pH probe of this pH meter is substituted for DrDAQ's one.
It seems that this pH probe is not out of order.

When I use picolog recorder release R5.08.6 and Windows Vista Home Premium SP1, DrDAQ indicate 1.10 in 0.1mol/L HCl solution and 12.30 in 0.1mol/L NaOH solution.
However, picopp.sys and DRDAQ32.DLL were substituted as follows.